Cada pregunta de este test está cronometrada.
Which of the major types of membrane proteins are bound to the surface of the membrane?
Integral proteins.
Carrier proteins.
Peripheral proteins.
Channel proteins.
Receptor proteins.
Systems that have energy added to them or energy removed from them are best described as which one of the following:
Open systems.
Closed systems.
Energy depositing systems.
Energy releasing systems.
None of the above.
Which of the following dictate the size and shape of erythrocytes?
Interactions with other cells in the vascular system.
The biological functions / roles of those erythrocytes
The intracellular content of those erythrocytes.
The size and shape of the parent (stem) cells from which those erythrocytes arise.
The size of the vascular system around which those cells must circulate.
Why does the composition of extracellular fluid differ from that of intracellular fluids?
Because ions are unable to cross the plasma membrane
Because the plasma membrane is freely permeable to all molecules.
Because the plasma membrane is impermeable to water.
Because the plasma membrane offers an impermeable barrier to all solutes.
Because the plasma membrane is selectively permeable to particular solutes.
Phospholipids can move within the plane of the membrane. Which of the following type of movement rarely occurs?
Lateral Diffusion (Exchanging places with a molecule within the same monolayer).
Rotation along their axis.
Flip-flop (Exchanging places with lipids in the other monolayer of a bilayer).
Flexion.
All the above
Oxidation and reduction occur simultaneously
What are Photoautotrophos?
Organisms that use light energy to synthesise organic molecules from CO2
Organisms which use energy from photons of light
Organisms that useenergy from light energy and organic substrate
Organisms which use energy derived from chemical bonds
Some enzyme-catalyzed reactions cease completely if their enzyme is absent
The rule that oxidation release energy, whereas reductions require energy input, applies to all chemical reactions, not just those that occur in living cells.
Some cells adjust their membrane by modifying the lipid composition of their membranes
The value of ΔH for a reaction is positive, therefore that reaction is catabolic.
Which of the following properties causes phospholipid molecules to form self-sealing, membrane bilayers when placed in water?
Phospholipid molecules are hydrocarbons
Phospholipid molecules are hydrophylic
Phospholipid molecules are hydrophobic
Phospholipid molecules are amphipathic
Phospholipid molecules are bipolar
Who pioneered the microscope?
Matthias Scheldien
Theodor Schawann
Anton van Leeuwenhoek
Rudolf Virchopw
Robert Hooke
Which option below is a type of prokaryote morphology?
Cocci (spherical)
Bacillus (rods/rod-like)
Spirochetes (spiral)
Vibrio ("commas"/curved rods)
Which of the following statements is incorrect?
Nuclei and mitochondria are surrounded by a double membrane
Hereditary information of a cell is passed on by its proteins
Lysosomes and peroxisomes are the site of degradation of unwanted material
Bacterial DNA is found in the cystosol
In the cytoskeleton, microtubules are composed of which of the following subunits?
Motor proteins
Alpha tubulin and beta tubulin
Kinesin
Dynein
Oligomers
Which of the following terms applies to cell-cell communication between adjacent cells and is dependent on physical cell-cell contact?
Autocrine
Endocrine
Intracrine
Juxtacrine
Paracrine
What technique below is not used to visualise the cytoskeleton?
Fluorescence microscopy
Live cell fluorescence microcospy
Computer-enhanced digital videaomucroscopy
Light microscopy
Electron microscopy
Which of the following membrane proteins penetrate the hydrophobic interior of the lipid bilayer?
Integral proteins
Peripheral proteins
Channel proteins
Carrier proteins
Receptor proteins
When G < 0, the reaction is exergonic. Which of the following statements is correct in relation to such reactions?
They can proceed forward and can occur spontaneously
They cannot occur spontaneously
They measure the thermodynamic spontaneity
They need energy to proceed
None of the above
Which one of the following statements is correct in relation to enzyme inhibition?
Enzyme inhibition is always irreversible
Reversible inhibition can be competitive and non-competitive
Enzyme inhibitors cannot be used as therapeutic agents
In non- competitive inhibition, the inhibitor competes with the substrate for the same binding site on the enzyme